Plastic spring assembly connected to a support tray

ABSTRACT

Corrugated plastic springs are substituted for metal coil springs in a chair, sofa, or the like. An annular flange is at the bottom of the spring and has a radial slot therein. A base tray support has a plurality of openings for receiving a respective spring therein. Each opening has a radial slot merging thereinto. One may insert the flange into the base tray slot and insert the edge of an opening into the slot on the flange and rotate the spring until the entire flange has proceeded under the base tray to provide a connection between the spring and base tray. A flexible spacer member is provided to keep the springs spaced from each other. The spacer member has a plurality of openings each receiving a top of a respective one of the springs therethrough.

United States Patent 1 [111 3,765,038 Curtis 1451 Oct. 16,973

[ PLASTIC SPRING ASSEMBLY CONNECTED TO A SUPPORT TRAY William R. Curtis, Newark, Del.

[75 Inventor:

[73] Assignee: Hercules Incorporated, Wilmington,

Del.

[22] Filed: May 17, 1972 [21] Appl. No.: 254,267

[52] US. Cl 5/351, 5/353, 297/DIG. 8 [51] Int. Cl. A47c 7/02 [58] Field of Search 297/452, DIG. 8;

[56] References Cited UNITED STATES PATENTS 3,242,512 3/1966 Beckman 5/353 2,737,666 3/1956 Herider et al 5/248 2,897,520 8/1959 Bradford 297/DIG. 8 3,262,137 7/1966 Beckman et al. ..-297/DlG. 8

Primary Examiner-Casmir A. Nunberg Attorney-Sheldon F. Raizes et a1.

[57] ABSTRACT Corrugated plastic springs are substituted for metal coil springs in a chair, sofa, or the like. An annular flange is at the bottom of the spring and has a radial slot therein. A base tray support has a plurality of openings for receiving a respective spring therein. Each opening has a radial slot merging thereinto. One may insert the flange into the base tray slot and insert the edge of an opening into the slot on the flange and rotate the spring until the entire flange has proceeded under the base tray to provide a connection between the spring and base tray. A flexible spacer member is provided to keep the springs spaced from each other. The spacer member has a plurality of openings each receiving a top of a respective one of the springs therethrough.

5 Claims, 7 Drawing Figures Patented Oct. 16, 1973 3,765,038

F|G.| FIG. 2

FIG.3 F|G.4 FIGS PLASTIC SPRING ASSEMBLY CONNECTED TO A SUPPORT TRAY It is an object of this invention to provide a corrugated plastic spring assembly for a chair, sofa, or the like which is economical and simple to assemble.

Other objects of the invention will become apparent from the following description with reference to the drawings wherein:

FIG. 1 is a side view of a chair cutaway to show a spring assembly;

FIG. 2 is a plan view of the spring assembly partially cutaway to show the upper surface of a base tray;

FIG. 3 is a bottom view of the spring;

FIG. 4 is an enlarged view of an opening in the base tray;

FIG. 5 is a bottom view of the flange of the spring being initially inserted into an opening in the base tray;

FIG. 6 is a bottom view of the flange after it is fully located on the under surface of the base tray; and

FIG. 7 is a partial section view along section lines 7-7 of FIG. 2.

Referring to FIG. I there is illustrated a chair 10 into which a plurality of plastic springs 12 are inserted. Referring to FIG. 2, the chair comprises a frame having four side members 14, 16, 18 and 20. A molded support tray or base member 22 is provided and comprises side walls 24, 26, 28 and 30, a bottom wall and a pair of flanges 34 and 36 integral with the upper part of the walls and 26, respectively, extending outwardly therefrom. This tray may be of any material but is preferably made of plastic. The bottom cpmprises four platforms 32, each separated from the other by a raised generally V-shaped reinforcing rib 35. Each platform has four equally spaced openings 38. The openings 38 are generally circular with the periphery thereof merging with a radially extending slotted portion 40.

Each plastic spring comprises a corrugated thin tubular wall which terminates in an annular flange 42 at the bottom thereof. The flange 42 has a radially extending slotted space 44 therein. An annular space 46 between the bottom-mostcorrugation 48 and the annular flange 42 is about equal to the thickness of the bottom platform 32 of the support tray 22. The width of the slot 44 is slightly greater than the thickness of the tray platform 32, for receiving the same therethrough, and the width of the slot is slightly greater than the thickness of the spring flange 42, forreceiving the same there through.

The length of slot 44 should be at least equal to the width of the flange 42 and the length of the slot 40 should be at least equal to the width of the flange 42.

The spring is attached to the tray by placing the flange 42 against the upper surface of the platform 32 and aligning the slots 40 and 44 approximately 120 from each other. One edge 48 of the slot 44 may be placed below the surface of the periphery of the opening 38 with a corresponding portion of the flange between the edge 48 of slot 44 and the edge 50 of the slot 40 being beneath the edge of the opening and the portion of the flange between the edge 52 of slot 40 and edge 54 of slot 44 overlying the corresponding edge of the opening 38. The portion of the flange between edges 52 and 54 is then pushed entirely 'under the corresponding edge of the opening 38 to take the position as shown in FIG. 5. The spring is rotated in a counterclockwise direction whereby the portion of the flange on top of the opening will be cammed by the edge 52 under the periphery of the opening until the entire flange is under the edge of the opening 38 and the bottom surface of the platform 32. As stated before, the space 46 between the bottom corrugation 48 and the flange 42 is approximately equal to the thickness of the platform wall 32 and thus a snug fit is provided between the spring and tray.

The tops of each spring are interconnected by a flexible plastic member 100 having a plurality of openings 102 for receiving a top of a respective spring therethrough. Each of the springs 12 has a circular planar surface 103 at the top thereof merging into an annular beveled edge 104 with the bottom portion 106 of the edge 104 being generally equal in diameter to the diameter of the opening 102. Each spring is snapped into the flexible sheet 100 by camming the edge of the opening 102 past the bottom 106 of the beveled edge 104 to provide an interlocking relationship between the spring and sheet 100. The circular neck 108 of the spring is about the same diameter as the opening 102 to provide a snug fit between the spring 12 and the flexible member 100. The sheet is sufficiently flexible to allow each spring to compress independently of each other and allow lateral movement of the springs toward each other but is rigid enough to prevent the springs from abutting each other. The normal padding and covering generally designated by reference numeral 110 is laid on top of the flexible sheet 100 and is stapled to the frame members l4, 16, 18 and 20. A cushion 112 is placed on top of the padding 110. The spring assembly works in the same manner as the coil spring assembly which the plastic springs replace.

While only one spring assembly is shown, more than one assembly could be used in a chair, sofa or the like by placing one assembly beside another in the same frame.

What I claim and desire to protect by Letters Patent 15:

l. A spring assembly comprising a base member having a plurality of generally circular openings therein, a plurality of corrugated tubular springs having a portion thereof extending through said openings, said portion being a peripheral radially outwardly extending flange, said flange having a slot therein extending to the outer periphery thereof and being at least as wide as the thickness of the edge of said openings, said openings each having a radially slotted portion the width of said portion being at least the thickness of said flange and r the length of said portion being at least the width of said flange, said slot and said slotted portion permitting the attachment of said spring to said base member.

2. A spring assembly as recited in claim 1 further comprising a flexible sheet having openings therein receiving the tops of a respective one of said springs therethrough, means for retaining said tops of said springs in said openings, said base member being supported by frame means, said sheet being sufficiently flexible to allow compression of any spring relative to the other spring and rigid enough to prevent the springs from abutting each other.

3. The spring assembly as recited in claim 1 wherein said assembly is located in a chair. i

4. The spring assembly as recited in claim 1 wherein said assembly is located in a sofa.

5. A spring comprising: a corrugated tubular wall terminating. at a peripheral radially outwardly extending flange at the bottom thereof, a slot in said flange extending to the outer periphery thereof and having a length equal to the width of said flange. v l 4 

1. A spring assembly comprising a base member having a plurality of generally circular openings therein, a plurality of corrugated tubular springs having a portion thereof extending through said openings, said portion being a peripheral radially outwardly extending flange, said flange having a slot therein extending to the outer periphery thereof and being at least as wide as the thickness of the edge of said openings, said openings each having a radially slotted portion the width of said portion being at least the thickness of said flange and the length of said portion being at least the width of said flange, said slot and said slotted portion permitting the attachment of said spring to said base member.
 2. A spring assembly as recited in claim 1 further comprising a flexible sheet having openings therein receiving the tops of a respective one of said springs therethrough, means for retaining said tops of said springs in said openings, said base member being supported by frame means, said sheet being sufficiently flexible to allow compression of any spring relative to the other spring and rigid enough to prevent the springs from abutting each other.
 3. The spring assembly as recited in claim 1 wherein said assembly is located in a chair.
 4. The spring assembly as recited in claim 1 wherein said assembly is located in a sofa.
 5. A spring comprising: a corrugated tubular wall terminating at a peripheral Radially outwardly extending flange at the bottom thereof, a slot in said flange extending to the outer periphery thereof and having a length equal to the width of said flange. 